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Information Sheet 3B: Quarrying - Limestone

Meldon Pool (SX 564922)

Quarrying of limestone at Meldon was taking place as early as the 18th century when a number of small quarrieswere being worked on the east side of the river. These workings are linked to the general improvement inagriculture in the 18th and 19th century which led to an increased demand for locally obtainable fertilisers.Seaweed, sea sand with a high shell content and burned limestone were all used, but in districts around northernDartmoor, distance from the coast meant that there was little chance of obtaining either sea sand or seaweed. Asa result, the very limited deposits of limestone in the Lower Carboniferous rocks of the area suddenly assumed agreat importance and Meldon lime which was of high quality, was much sought after. The burnt lime was spread

onto fields to “sweeten” the ground by reducing the acidity of the local soils and increase their fertility.

‘Meldon limestone quarry workers, c.1900’ (Source: Museum of Dartmoor Life, Okehampton)

An estate map of Okehampton Park of 1790 shows a small lime kiln, used for burning the limestone, which is stillvisible today, built against the edge of what seems to be an even earlier quarry on the east side of the WestOkement river. The quarried lime was taken to a charging platform  at the top of the kiln and tipped down its

circular shaft, sandwiched between layers of charcoal. A fire was ignited at the bottom of the kiln through a firegrate inside the arch at the back and the mixture of limestone and charcoal was burned slowly at hightemperature. When cooled, the resulting quick-lime was shovelled out in lump form through the fire grate straightonto carts and taken away by local farmers.

Map and documentary evidence reveals that the eastern kiln was abandoned for a period in the early 1800s butwas later to serve the large limestone quarry on the west side of the river. The extent of the older quarries in theeastern area is now difficult to determine as they have been infilled and obscured by later workings.

Workings on the west side of the river were very impressive and concentrated on a steeply dipping band oflimestone, with the now flooded quarry forming Meldon Pool. The excavation was over 40 meters deep andoccupies virtually the whole extent of the surface outcrop of the limestone. To extract limestone, a considerable

quantity of overlying rocks of little economic value had to be removed and in doing a large amount of waste wascreated. Whilst the quarry on the west side was still fairly small, map evidence shows that buildings, including

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more limekilns and a house clustered around its northern edge. As the quarry expanded these were destroyedand replaced by structures further to the north. Tipping of waste also encroached and destroyed some of theselater 19th century buildings and continued beyond the viaduct.

Meldon Pool, the flooded Meldon limestone quarry (Photo: Kevin Page 2005)

The older, eastern lime kiln (Photo: Kevin Page 2005)

Only three structures have survived; the most impressive being the limekiln situated under the westernembankment of the viaduct built between 1874 and 1885. Its single draw hole is strengthened by iron stays and

the mixture of stone used in its construction reflects the variety and complexity of Meldon’s geology. The kiln’scharging platform was fed by an inclined tramway some 100m long using a winch system of haulage - the ironanchoring point and the chains at the kiln end still survive in situ.

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The larger western limekiln (Photo: Kevin Page 2005)

To the south of the kiln are the ruins of the weigh-house building, fronted by its weighbridge with a cast ironbedplate showing the maker’s name, Bartlett and Son of Bristol . The footings of a larger building lie to the southof the weigh-house.

The remains of the base plate of the weigh-house (Photo: Kevin Page 2005)

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Lack of space created by the river on one side and the steeply rising ground on the other, meant that disposal ofwaste was a continual problem and was solved by the creation of linear waste heaps. Waste was removed by

trucks running on temporary rails and dumped into well defined linear heaps on both sides of the river. On thewest side of the river, the embankments were revetted and the sites of two former bridges over the trackways aremarked by stone abutments. The finger shaped dumps on the eastern side are the most striking earthworks onthe site, their history is complex and when the quarries were in full production their form would have changed onan almost hourly basis.

‘Finger dumps’ on the south side of the West Okement River (Photo: Kevin Page 2005)

Keeping the deep quarry workings dry was a considerable problem and the solution seems to have been to usepumps driven by waterwheels positioned on the east side of the river, immediately south of the footbridge. Twowheels, probably not operating in tandem, were served by a number of leats and reservoirs. The leats took waterfrom both the West Okement and the Red-a-ven using a number of water channels following sinuous coursesacross the south western quadrant of the area.

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Water wheel on the east side of the River Okement, late 19 th century?(Source: Museum of Dartmoor Life, Okehampton)

The southern waterwheel was fed directly by a leat, whilst that to the north, near the modern footbridge, had amuch more elaborate and impressive water system using initially one and then two reservoirs and a launderbank. The northern wheel, which had a diameter of about 5.5m, and the smaller reservoir are shown on the 1840Tithe map.

Water wheel pit on the east side of the West Okement River – possible the site of the wheel in the

previous photograph…(Photo: Kevin Page 2005)

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By 1885 the higher West Okement leat was supplying a larger semi-circular reservoir east of the earlier one andpowering the same wheel. The actual method of pumping is unclear though the waterwheels motion was

transmitted by flat rods across the West Okement and transformed to a pumping action by some form ofreciprocating gear in the vicinity of the small structures overlooking the quarry. Today the site of the wheel pitsare marked by partially filled, stone-lined rectangular depressions, behind which are two smaller holes to hold theweights used in tensioning the flat rods powered by the wheels.

It is uncertain when limestone production finally ceased at Meldon but by 1885 it is seems clear that the emphasisof activity had moved to exploiting the aplite (see Information Sheet 3F).

Authors: J. Marchand & R.E.Page 2006